Gift: ERLA Model S-11 #16149 - Videokarma.org TV - Video

Fran604g · #1 08-09-2019, 09:03 AM

Hiya folks,

Been a while, I hope everyone is still kickin' and doing well. I was recently gifted a fairly nice and eminently restorable ERLA S-11, and I'm looking for a schematic.

I've done the precursory web searches, but turned up a big fat nothing-burger. Thus, I'm hoping for a little guidance here, to help me understand what the circuitry is, and so that I can measure C's and R's to see if they're still in reasonable condition, etc.

Thanks in advance!

Fran Pratt

Here's a few photos (the last one of the ant. connections paper label stolen from the interwebs - mine is missing):

Sandy G · #2 08-09-2019, 12:39 PM

Damn nice gift ! Take the guy out & buy him/her a Steak Dinner... From what I've seen these 3 dialers pretty much worked the same way. Somebody more experienced w/them could likely tell you how to hook one up, & could see if it works. & could how to REALLY fine tune one in..

Fran604g · #3 08-10-2019, 04:58 AM

Quote:

Originally Posted by Sandy G

Damn nice gift ! Take the guy out & buy him/her a Steak Dinner... From what I've seen these 3 dialers pretty much worked the same way. Somebody more experienced w/them could likely tell you how to hook one up, & could see if it works. & could how to REALLY fine tune one in..

Thanks, Sandy! He's a really good kid (kid meaning in his mid 20's); we swap acoustic phono goods frequently, and he's incredibly knowledgeable of recording artists from the late 19th/early 20th centuries. His willingness to help this gimped up aging guy, restores my faith in his generation.

He also brought me a bunch of good 78's, including a couple outside start Pathe's, some Victor electrical's, and a very nice Columbia "Flag Label" Bessie Smith Love Me Daddy Blues/Women's Trouble's Blues #14060-D.

He's a true mensch!

bgadow · #4 08-10-2019, 09:12 PM

I've recently been playing around with an Atwater Kent 20, got it working well. I have a number of other "3-dialers". I'm trying to get better at working on them and understanding the circuitry, which hopefully will make me better at diagnosing more complicated things. There really isn't much to go wrong. Original grid leaks are usually bad; on the A-K I rebuilt the old one, a first for me, easy and a satisfying repair. Mine had an open pot which was also an easy fix. That was pretty much it, the tubes that came with it were all okay. It's handy to have some you can swap as I think that's more reliable than a tube tester in this case.

I have an ERLA "2-dialer" that I think was built from a kit they sold. I sorta got it working once but not very well. Need to try again someday.

Fran604g · #5 08-11-2019, 07:10 AM

I'm assuming that the circuitry of this "5 in a row make it go" (as a friend described it) ERLA should be very similar to others of the era, but is it wrong for me to think the R values would be identical to others?

Best,
Fran

Fran604g · #6 08-11-2019, 07:38 AM

Hiya folks,

I found this schematic whilst cruising the 'net, it appears this radio is only a TRF, without added neutrodyne circuit(s), correct? I can't vouch for the accuracy of this schematic.

Fran604g · #7 08-11-2019, 08:29 AM

Please bear with me as I muddle through my various stages of reacquainting myself with the tech I haven't thought about for a very long time. I now understand there is NO regenerative circuitry involved, only simple 3 tuner TRF.

I'll get there...

Fran604g · #8 08-11-2019, 09:16 AM

I'm convinced that's the correct schem for my radio, parts counts are right. I poked around and found matching R's. I'll see if I can find values for the capacitors.

Fran604g · #9 08-11-2019, 03:52 PM

Did a little cleaning today. I gotta say, there doesn't appear to be any reason this radio shouldn't work. I managed to adjust the three tuning capacitors so the plates aren't rubbing when being turned. We'll see, I haven't checked for continuity, and resistances yet.

I just got excited and wanted to show you folks how she cleaned up so far.

bgadow · #10 08-11-2019, 09:03 PM

Looks very nice! Maybe that battery is weak

Fran604g · #11 08-12-2019, 07:02 AM

Quote:

Originally Posted by bgadow

Looks very nice! Maybe that battery is weak

Fran604g · #12 08-12-2019, 11:47 AM

Sooooo...everything measures fine, BUT, the schematic I found doesn't actually match my radio, other than parts count and most of the component values. The 2 rheostats in mine are both 25 ohm, and one (from the detector F-) is connected to only the low side of the pot, so I'm missing a connection going to somewhere.

The wiring is all kind of messed up on the schem. - and I just realized the way it's drawn, the tubes are shown in mirror image to the actual socket connections looking at them from the bottom, so whether you're looking down from the top, or up from the bottom everything is out of whack. I didn't notice that from the quick glance I took of that schematic.

Am I crazy?

It's killing me...

I'll have to redraw it, if I'm going to have any understanding of this radio.

I'll update as progress warrants. Meanwhile, a couple more photos.

Electronic M · #13 08-12-2019, 12:28 PM

Most schematics asside from some 1920s ones have absolutely no correspondence between position of part on the page and mechanical location of part on the chassis.... honestly if you understand circuit theory it is best that the schematic not include mechanical layout to make the power and signal flow easier to read and follow.

The best thing to do is to if you are having trouble matching things on the schematic to the chassis is label each part with the letter-number designator on the schematic (some 20s schematics may need you to add your own designators). Some parts are easy to identify, and if you trace unknown parts to known then look at everything hooked to the known on the schematic you can trace it out.

TV collectors like me have to do this activity accurately on 20-40 tube TV sets regularly.

jr_tech · #14 08-12-2019, 06:04 PM

I may be wrong, but it looks like the grid-leak detector is at one end of the chassis and the 2 audio amp stages at the other end, with the tuned RF stages in the middle. Was this some clever arrangement to reduce feedback? or am I mistaken in my assessment of the layout?

jr

Fran604g · #15 08-12-2019, 06:53 PM

Quote:

Originally Posted by jr_tech

I may be wrong, but it looks like the grid-leak detector is at one end of the chassis and the 2 audio amp stages at the other end, with the tuned RF stages in the middle. Was this some clever arrangement to reduce feedback? or am I mistaken in my assessment of the layout?

jr

You're correct, in regard to the layout.